Cleveland Museum of Art:
These [3rd century] symbolic sculptures... may all share a common origin since the entire group was purportedly unearthed together from a large pithos, or jar. The original find-spot remains unknown. Other reasons for believing the sculptures belonged together are their common material, their similarities of style and execution, and the burial deposits over their surfaces. Recent technical analysis has helped identify the Roman Imperial quarries at Docimium in Ancient Phrygia as the source for the marble from which the sculptures were carved. The Docimium quarries supplied the Roman Empire with high-quality marble in the form of unfinished blocks that were used for sculpture, paving, and veneer. Known as the Jonah Marbles, this sculptural ensemble astonished the art world when it was introduced to the public in 1965, not only for its superb quality and condition, but also for its very survival.
These sculptures conform to a language of symbols developed by early Christians... The four figures of Jonah depict incidents from the biblical story. Swallowed by a great fish for his disobedience to God, Jonah spent three days within the beast's stomach. After repenting, he was disgorged unharmed. Jonah Swallowed and Jonah Cast Up were understood by early Christians to represent the death and resurrection of Christ. The gourd vine under which Jonah rests was another symbol of the resurrection... The figure of Jonah Praying with arms extended in the orant position may represent either his repentance within the whale's belly or his thankfulness after his deliverance.